DESCRIPTION: Stressful features of work organization, including long work hours, have recently been identified as risk factors for blood pressure elevation and cardiovascular disease (CVD) and have been suggested as risk factors for work-related musculoskeletal disorders (WMSDs). The proposed study has two primary specific aims, to determine: 1) associations between extended work hours, ergonomic risk factors, other psychosocial job stressors, and WMSDs; and 2) associations between extended work hours, other psychosocial job stressors (including job strain, effort-reward imbalance and shift work), blood pressure elevation and CVD risk. The study population includes white-collar and blue-collar men and women from the health care, transportation, and manufacturing industries, many of whom currently use overtime extensively. The study is also designed to examine the effect of characteristics of overtime, to assess how overtime may interact with other stressful features of work organization, ergonomic stressors or demographic measures, and to investigate the impact of recent changes in the organization of work on work hours, psychosocial job stressors, ergonomic risk factors, and work climate. Initial efforts will include analyses of available employer records on work hours and WMSDs in the transportation and manufacturing industries, and secondary analysis of existing medical data bases in the health care industry. A population-based case-control study of incident cases of WMSDs will be conducted among health care workers. 200 cases and 200 healthy incidence-density-matched controls will be interviewed in person. Ergonomic observation of an individual representing each job title held by study participants will be conducted. 40 job-matched controls will also be selected from workers in the same job titles as cases to assess information bias in the cases, and to allow substitution of job-matched controls' biomechanical job exposures for cases in whom such data cannot be collected. A cross-sectional study of a random sample of 400 employees, stratified by overtime use, from participating employers in various industries, will be conducted to investigate risk factors for blood pressure elevation and CVD. Participants will have their blood pressure measured while working using an innovative method (work site point estimates) to obtain a valid estimate of mean workday blood pressure. A sub-sample of 100 employees will be followed over 2 years and have their blood pressure measured during periods of high vs. low overtime.